Friedman's statement that ‘most people who are violent are not mentally ill, and most people who are mentally ill are not violent’ remains apposite, but recent US gun killings inevitably reawaken the debate. In a moving editorial in the New England Journal of Medicine, Malina and colleagues compellingly compare gun lobbyists to a cancer growing in the mutated cells of the psychological and sociological make-up of the United States. What is the contribution of mental health to this problem? Estimates suggest it might have impacted the trajectory of 3–5% of the approximately 33 000 US gun deaths in 2013. Sadly, one imagines that psychiatry had a far bigger role in terms of the subsequent psychological impact on their relatives, witnesses of the violence, and the further 84 000 who survived such assaults that year. Against the backdrop of halting convulsions towards legislative change, the authors reason that mental healthcare cannot be held responsible for what they label the impossible task of identifying anyone who might conceivably start shooting others.